changes between imaa-01 and -02

This might be helpful for reviewing the new draft.

AMC

Issues that were open and are now fully closed (not mentioned):

    Should IMAA support case-sensitive mail exchangers?  No.

    Should IMAA keep the requirement about recognizing fullwidth
    at-signs?  Yes.

    Should ideographic full stop be converted to ASCII full stop in
    local parts, as is done for domain name separators?  No.

    Should IMAA require that fullwidth quotation marks and backslashes
    be recognized?  No.

Issues that were closed-but-could-be-reopened and are now fully closed
(not mentioned):

    Should local parts be processed in segments?  Yes.

Issues that were open and are now closed-but-could-be-reopened:

    Should the 59-character limit on the Punycode encoder output
    be relaxed?  No.

    Should hyphens be protected?  Yes.

    Should the IDNA ACE prefix be resused for IMAA (which is an option
    only if hyphens are not protected)?  No.

Issues that remain open:

    Should we remove the recommendation that applications avoid altering
    the quoting of a local part when applying ToASCII/ToUnicode would
    have no other effect?

    Does IMAA say the right things about stored strings versus query
    strings?

Inserted section 6 as a first attempt at addressing the stored/query
issue.

Changed "mail address" to "mail address (or part of a mail address)" in
the definition of mail address slot and in section 3.1 requirement 2.
(Motivation: /etc/aliases contains slots for just the local parts, while
the associated domain parts are likely to be in separate slots in some
sort of local_domains parameter of the MTA config file.)

In order to protect hyphens, changed "ACE prefix" to "ACE infix" and
tweaked ToASCII steps 5b,e and ToUnicode steps 5a,b and section 5.

Added section 3.2.2 to discuss the issue of local parts and domain names
getting transplanted from one side of the at-sign to the other.

In section 4, split step 5 into 5 & 6 (they had previously been combined
and presented out of order).

In ToUnicode tweaked steps 3 and 8.  There was no need to save a copy in
step 3, because step 8 can use the original input instead.

Made all the citations descriptive.  Previously some had been
descriptive, like [STRINGPREP], while others had been numeric, like
[RFC2822].  No change to the references themselves, except to add the
informative reference for [DNS], which had been missing (it is cited in
the introduction in the explanation of the differences between IDNA and
IMAA).

Some inconsequential rewording.